1. Field of the Invention
The present invention relates to a dicing blade for use in cutting an object such as a non-baked ceramic material and to a method of producing an electronic component using the dicing blade.
2. Description of the Related Art
In production of an electronic ceramic component, a multilayer ceramic mother object is prepared and cut in its thickness direction into individual pieces of multilayer objects to be formed into electronic ceramic components. Thereafter, the individual pieces of multilayer objects are baked into a sintered form. Finally, an outer electrode is formed on the outer surface of each sintered object.
A force-cutting blade is most often used to cut a raw ceramic material such as a multilayer ceramic mother object. On the other hand, in the production of semiconductor chips, a dicing blade is widely used to cut a wafer into chips.
An example of a dicing blade is disclosed in Japanese Unexamined Patent Publication No. 6-188308. FIG. 6 illustrates the structure of a dicing blade 51 disclosed in the patent cited above, wherein the dicing blade 51 includes a ring-shaped cutting blade 53 attached to a holder 52. A cutting edge is formed on the peripheral rim of the cutting blade 53. A plurality of grooves 54, extending in radial directions, are formed on opposite surfaces of the cutting edge 53 such that the grooves 54 result in a partial reduction in the thickness of the cutting edge 53.
The grooves 54 formed on the cutting edge allow a sufficient amount of cooling water and purified washing water to be supplied to a cutting edge thereby cooling the cutting edge 53 and removing swarf therefrom.
When using the above-described dicing blade, a relative large amount of swarf is generated when an object being cut has a large thickness. When the object is cut at a high speed, swarf is not removed smoothly enough through the grooves 54.
As a result, a large load is imposed upon the dicing blade and the surface of the object being cut becomes rough. Furthermore, a large wobble is induced in the dicing blade which reduces cutting accuracy.
When a non-baked multilayer mother object is cut by a dicing blade into individual pieces which will be further formed into electronic multilayer ceramic components, the non-baked multilayer mother object includes a binder contained in a ceramic material and also includes a conductive paste used to form inner electrodes. As a result, swarf generated during a cutting process includes conductive paste particles and binder particles which can cause swarf to stick to a cutting surface of the object being cut. The resultant sticky swarf cannot be easily removed. When the object being cut has a large thickness, the above problem is serious.
It is an object of the present invention to provide a dicing blade capable of cutting an object while smoothly removing swarf even when the object has a large thickness, and thus making the dicing blade capable of precisely cutting the object without causing the surface of the object being cut to be significantly contaminated. It is another object of the present invention to provide a method of producing an electronic component using such as dicing blade.
According to an aspect of the present invention, there is provided a dicing blade comprising a ring-shaped cutting blade having a cutting edge formed on the peripheral rim thereof, said ring-shaped cutting blade having at least one slit formed in a thickness direction of the dicing blade on the peripheral rim and extending to the cutting edge, the depth of the at least one slit, as measured in the radial direction of the dicing blade, being greater than the thickness of an object to be cut.
Preferably, the slit is formed such that the width of the slit decreases from the cutting edge toward the center of the dicing blade.
Furthermore, the slit is preferably formed in an arcuate shape when viewed in a direction perpendicular to a plane in which the cutting edge of the ring-shaped cutting blade lies.
According to the method of the present invention, electronic components are formed by:
providing a non-baked multilayer object having a plurality of inner electrodes formed therein;
cutting the non-baked multilayer object along its thickness direction into a plurality of individual pieces of multilayer objects using a ring-shaped cutting blade having a cutting edge formed on a peripheral rim thereof, the ring-shaped cutting blade having at least one slit formed in a thickness direction of the blade on the peripheral rim of the cutting blade and extending to the cutting edge, the depth of the at least one slit, as measured in a radial direction of the ring-shaped cutting blade, being greater than the thickness of the multilayer object.
The width of the slit preferably decreases from the cutting edge toward the center of the dicing blade and the slits are preferably formed in an arcuate shape as viewed in a direction perpendicular to the plane in which the cutting edge lies.
A plurality of slits, preferably four, are formed in the peripheral rim.
The inner electrodes are formed of a conductive paste and ceramic electrodes are located between respective pairs of the inner electrodes.
After the non-baked multilayer object has been cut into small pieces using the cutting blade, the individual pieces of multilayer objects are baked to form sintered objects. Finally, one or more outer electrodes are formed on the sintered objects.